In T 9/81 (OJ 1983, 372) the board held that combined preparations, the individual components of which represented known therapeutic agents, might be protected in a formulation corresponding to Art. 54(5) EPC 1973 (now Art. 54(4) EPC) even when claimed as a kit-of-parts, providing those components formed a functional unity (true combination through a purpose-directed application. Claim 1, which was drawn up in the form stipulated in Art. 54(5) EPC 1973, referred to a combined preparation containing an oxazaphosphorin cytostatic agent and the sodium salt of 2-mercapto-ethane-sulphonic acid as therapeutic active ingredients. The first-mentioned component of the product was known, and the second was a known mucolytic agent. According to the documentary prior art available to the board, the two active ingredients had never been used together for a new joint effect and were unknown as a composition. The active ingredients which were administered preferably at the same time according to the invention did not therefore represent a mere aggregate of known agents, but a new combination with the surprising, valuable property that the severe side-effects to be expected when administering the cytostatic agents were absent as a result of the detoxifying effect of the sodium 2-mercapto-ethane-sulphonate.
Claim 1 referred to a product which was limited to simultaneous, separate or sequential use in cytostatic therapy. In the board's judgment, it followed from this indication of purpose that the components were no longer necessarily present as a union, e.g. in composition, since the components would not otherwise be available for separate or sequential application. The board stated that as a kit-of-parts, however, it was not necessarily a true combination in view of the physical separation of the individual components. The mere loose association of known components did not in itself turn them into a functional unity in which a necessary and direct interaction between the components was a precondition for the purposive use (e.g. lock and key, match and striking surface, two-component adhesive). Although the components in the claimed combination did not enter into such direct interaction with each other, the indication of purpose for the combined therapy might re-establish the unity of the product as a functional amalgamation of its two components, if it represented a genuine restriction to the specified application. In so far as the components could not attain the advantageous effect according to the invention independently of each other, the joint effect justified the unity of the combined product as a result of the limitation by the indication of purpose of the area of protection of the claim under the conditions laid down in Art. 54(5) EPC 1973, even if the components were presented side-by-side and not as a union. Since the individual components of the combined product in the present claims had themselves known therapeutic applications, these claims, by expressly including the separate presentation of those components, were indeed to be regarded as limited to the joint use of the combined products, so that the individual applications according to the state of the art were excluded.